A major clinical trial funded by JDRF has found that people with type 1 diabetes who used continuous glucose monitoring (CGM) devices to help manage their disease experienced significant improvements in blood sugar control. Results from the multi-center study were presented on September 8 during the European Association for the Study of Diabetes’ annual meeting in Rome, and portions of the data are published in the October 2 issue of The New England Journal of Medicine. The CGM study—a randomized, controlled trial involving 322 patients ages eight to 72 years—took place at 10 academic, community, and managed carebased practices. Patients were assigned to either CGM or to a control group using standard blood sugar monitoring, and were followed for 26 weeks to assess effects on blood sugar control, principally by measurement of the HbA1c level. Three age groups were analyzed separately: eight to 14 years of age, 15 to 24 years of age, and 25 years of age or older. Among the study’s major findings:

Improvements in blood sugar control were greatest for CGM patients 25 or older, whose HbA1c levels decreased (improved) during the study by an average of 0.53 percent compared with control patients. Improvements in secondary measurements were also significantly greater in CGM patients including the percentage of patients able to achieve an HbA1c level below seven percent, or a 10 percent relative or 0.5 percent absolute drop in HbA1c. The improvement in HbA1c occurred without an increase in hypoglycemia (low blood sugar).

In children ages eight to 14, the average decrease in HbA1c was not significantly different in the CGM and control groups; however, those in the CGM group were more likely to lower their HbA1c by at least 10 percent and achieve HbA1c levels below seven percent compared with the control group.

Fifteen-to-24-year-old CGM patients, as a group, did not experience significant improvements in glucose control compared with the control group.

CGM use varied with age, and although the study was not specifically designed to assess the effect of frequency of CGM use on HbA1c, an analysis suggested that patients within all three age groups, including teens and young adults, who used the device at least six days a week had substantially lower HbA1c levels after six months compared with patients who used CGM less than six days a week.